Spoiler warning: secrets about the end of Guardians of the Galaxy Vol. 3 will be revealed in what you're about to read. Stop now if you don't want to know any more.

Guardians of the Galaxy Vol. 3 features the big screen debut of many new MCU characters - Will Poulter as Adam Warlock, Chukwudi Iwuji as the High Evolutionary, to name a few - but none will end up taking up more space in your mind than Maria Bakalova as Cosmo the Spacedog.

Having made her official debut in the recent Disney+ streaming TV special The Guardians of the Galaxy Holiday Special in 2022, Maria Bakalova plays a significant part of Guardians of the Galaxy Vol. 3 - and the character's past in comics gives us some clue as to what her MCU future might hold.

The former Soviet test pilot might have been lingering in the background of the Guardians movie franchise to this point, but they’ve been part of Marvel’s comic book canon for more than a decade, teaming with some of the company’s biggest cosmic characters to save the galaxy on a semi-regular basis. Want to know more about everyone new favorite four-legged friend? Keep reading.

Who is Cosmo?

The secret origin of Cosmo the Spacedog — to give the character their full name — is a surprisingly sweet revision of genuinely tragic real life history. In our world, dogs were used by scientists during test flights for the Soviet space program in the '50s and ‘60s; it’s estimated that somewhere in the region of 57 flights were 'manned' by dogs, with many dying in the process.

The most famous of these dogs is Laika, the first animal ever sent into orbit back in November 1957, whose death was originally reported as the result of suffocation after the air in their capsule ran out, only for it later to be revealed that she actually died far earlier in the flight due to stress and over-heating. Cosmo, who first appeared in 2008’s Nova #8 by Dan Abnett, Andy Lanning, and Wellinton Alves, is the Marvel Universe happy ending alternative to that real life tragedy: a story in which a Soviet space dog didn’t just survive in space, but thrived — after, just like the Fantastic Four, being exposed to cosmic rays and getting super-powers as a result.

In Marvel’s comic book canon, Cosmo is a telepath who serves as the security chief on Knowhere, a floating city in space built from the remains of a severed Celestial head that serves as a home for all manner of drifters who couldn’t quite find a place anywhere else in the galaxy. As such, he’s worked with both the Guardians of the Galaxy and the Nova Corps on multiple occasions, proving himself to be a brave and loyal companion to anyone fighting to make space a better place. He is, unmistakably, a good boy.

Who is Cosmo in the MCU?

Fans of super-powered cosmic canines might have glimpsed Cosmo in a couple of cameo appearances in the first two installments of the Guardians of the Galaxy franchise; she — yes, she — showed up in 2014’s first movie as part of the Collector’s museum menagerie of treasures (don’t worry; they were freed before too long), and then in a blink-and-you’ll-miss-it cameo in the post-credit scene of the 2017 sequel.

Surprisingly, Cosmo’s most significant MCU appearance to date isn’t actually Cosmo, exactly — a parallel-reality version of the pup shows up as a member of the Ravagers in the 'What If… T’Challa Became a Star-Lord?' episode of the Disney+ What If…? series.

The Guardians of the Galaxy Holiday Special was, in a way, Cosmo’s proper introduction to the Marvel Cinematic Universe, in that it actually introduces her as a character, and not just a background cameo or punchline to a Howard the Duck joke; it also introduces Maria Bakalova (Borat Subsequent Moviefilm) as the character’s voice actor.

Despite the gender swap, the MCU Cosmo’s backstory is the same as her comic book counterpart's: a dog launched into space as part of the early Soviet space program who, after becoming lost in space and exposed to cosmic radiation, ends up on Knowhere and becomes part of the scenery there. Going forward from here, though, her story is likely to be something very different from anything she’s gone through before, now that she's actually a member of the Guardians of the Galaxy proper.

She's what?

Yes, Cosmo has officially joined the Guardians as of the mid-credit sequence at the end of Guardians of the Galaxy Vol. 3. It only makes sense, given that it was her telekinesis that made the rescue of the refugees from the High Evolutionary's capture possible, by keeping Knowhere "airtight" with the High Evolutionary's ship in deep space. Also, she's a very good dog; that counts for something, too.

What are Cosmo’s powers?

As the result of being exposed to cosmic rays, Cosmo has significant psychic abilities, including both telepathy and telekinesis; he’s been shown to be able to both project blasts of concussive force and create strong shields against physical attack, as well as share his thoughts into others’ minds. The cosmic rays also seem to have expanded his lifespan considerably, given that the space race was roughly 70 years ago, and yet he’s still running around as healthy as ever. Maybe we should all get ourselves some of those cosmic rays.

(No, don’t; please remember the fate of Laika.)

What’s the future like for Cosmo?

Now that Cosmo is officially a Guardian herself, it feels as if the sky's the limit for the character. After all, if the success of Groot in the last few years proves anything, it’s that the combination of space and cute can go a very long way with MCU fans. (Perhaps even convincing Marvel to start publishing comics featuring the character again; we can only hope.)

The final installment in James Gunn’s trilogy (well, trilogy-and-a-bit, with the addition of the Holiday Special on Disney+), Vol. 3 promises to bring the long-running story of the team to a satisfying end after nine years, as well as opening up space just a little bit wider for future Marvel stories to explore. It's a film that Popverse's own Tiffany Babb enjoyed a lot, calling it "the best superhero movie of the past six years" - which is high praise indeed.

Guardians of the Galaxy Vol. 3 opens in most theaters May 5, 2023. Buy tickets on Fandango or Atom Tickets.

Get ready for the new film with our comprehensive Guardians of the Galaxy Vol. 3 guide.